Aenima, commonly mistaken for the word Enema, has a totally different meaning. The word has been traced back to legends of a sex god named Aenima. He was believed to have had sex with all the moms of the Ashen Empires players. He was famous for the 1 month sex session with Pope John The Baptist’s mom, Mary The Nun.

Cuz I'm praying for rain
And I'm praying for tidal waves
I wanna see the ground give way.
I wanna watch it all go down.
Mom please flush it all away.
I wanna watch it go right in and down.
I wanna watch it go right in.
Watch you flush it all away.

Time to bring it down again.
Don't just call me pessimist.
Try and read between the lines.
I can't imagine why you wouldn't
Welcome any change, my friend.

Ænima is a spiritual term meaning an Atlantis type cataclysm, meaning land sinking underneath water. The inside cover (where the CD sits) has a holograph of California sinking beneath the ocean, thus Ænima. The lyrics in the song suggest, “Your ass is going to be swimming in Arizona Bay”. Another contribute to the correct definition.

And for the opinion that the Ænima album is the best one, all Tool albums are great, each one is changed just a little bit, makes them worth listening too!

Tool's album title "Aenima" is a combination of the Latin word "Animus", meaning - intellect, memory, consciousness, mind.
and
"Enema", meaning - the procedure of introducing liquids into the rectum and colon via the anus, for cleansing purposes, etc.